Energy and exergy analysis of an integrated organic Rankine cycle-vapor compression refrigeration system

In the present study, the performance of an integrated organic Rankine cycle-vapor compression refrigeration (ORC-VCR) system is investigated from the viewpoint of energy and exergy analysis. The system performance was represented by system coefficient of performance (COPS), system exergy efficiency (ηe,sys), turbine pressure ratio (TPR), and total mass flow rate of the working fluid for each kW cooling capacity (ṁtotal). Many common and new hydrocarbons, hydrofluorocarbons, fluorocarbons, hydrofluoroethers, and hydrofluoroolefins were suggested as working fluids. The influences of various parameters such as the boiler, condenser, and evaporator temperatures, along with compressor and turbine isentropic efficiencies, on the system performance were also investigated. The results revealed that the best system performance was attained with the uppermost critical temperature dry working fluid. Among all suggested candidates, R602 is shown to be the most suitable working fluid for the ORC-VCR system from system performance and environmental issues viewpoints. However, due to its flammability, extra precautions should be taken. The highest COPS, ηe,sys, TPR, and the corresponding ṁtotal using R602 are 0.99, 53.8%, 12.2, and 0.005 kg s−1 kW−1, respectively at a condenser temperature of 25 °C and the typical values for the rest parameters.